Copper has a relatively high conductance compared to many other elements, and accordingly can be desired for utilization as a wiring layer in various circuitry applications. For instance in semiconductor processing applications, it can be desired to provide copper wiring layers as electrical paths to various integrated circuit components.
It is often desirable to cover and/or line conductive lines, such as copper-containing conductive lines with conductive diffusion barrier layer materials. Such materials are intended to preclude, or at least reduce, the diffusion of materials into copper-containing lines, as well as to preclude copper from diffusing out of such lines into surrounding material. Some conductive diffusion barrier materials include cobalt. Such materials can be difficult to clean. Further, such cobalt-containing materials will frequently have an outer surface to which electrical connection with other conductive components is ultimately to occur. The formation of such electrical connection will frequently involve providing another conductive material over the surface of the cobalt-containing material, for example through an opening formed in dielectric material(s). The conductive material is intended to physically contact the surface of the cobalt-containing material to form an electrical connection therewith. However, if the surface of the cobalt-containing material is partially or entirely covered with debris (for example an etching residue), the physical connection of the conductive material and the cobalt-containing surface can be impaired. Such can lead to attenuation of the electric current passing between the cobalt-containing material and the conductive material formed thereover.
While the invention was motivated in addressing the above identified issues, it is in no way so limited. The invention is only limited by the accompanying claims as literally worded, without interpretative or other limiting reference to the specification, and in accordance with the doctrine of equivalents.